You have 7 years to learn Mandarin

A recent article in Fortune Magazine talks about the rise of China as a economic superpower. I've always heard China would be the leading economy by the middle of this century, replacing the U.S., but this article predicts an even quicker time frame. That is, in 7 years (2015) China will be the largest economy in the world. However, this prediction is based on something other than the traditional approach of measuring each country's GDP.

Essentially, it suggests that we are now entering an era where the country with the largest number of people will naturally be the largest economy. There's no mention of India in all of this which I believe should surpass China in population by 2030.